useAppLifecycle

A react native hook to run code when your app is launched, focused and blurred.

Install

yarn add @pachun/react-native-use-app-lifecycle

Usage

In your topmost-level component:

import useAppLifecycle from "@pachun/react-native-use-app-lifecycle"

const App = () => {
  useAppLifecycle({
    onLaunch: () => console.log("launch"),
    onFocus: () => console.log("focus"),
    onBlur: () => console.log("blur"),
  })

  return <></>
}

export default App

Motivation

Test driving code is nice. Writing tests for ref code sucks. Use this package to avoid TDDing ref code and improve the readability of your tests a little bit.

I use this package to check for and download Over-The-Air (OTA) expo updates.

Tests

import { renderRouter, act } from "expo-router/testing-library"
import useAppLifecycle from "@pachun/react-native-use-app-lifecycle"

jest.mock("@pachun/react-native-use-app-lifecycle", () => ({
  __esModule: true,
  default: jest.fn(),
}))

describe("foregrounding the application", () => {
  it("does stuff", async () => {
    let triggerAppForeground
    jest.mocked(useAppLifecycle).mockImplementation(({ onFocus }) => {
      triggerAppForeground = onFocus
    })

    renderRouter("src/app", { initialUrl: "/" })

    await act(() => triggerAppForeground!)

    // expect stuff
  })
})

Contributing

PRs are exciting 🤟 Bump the version number in package.json and open one.

• Please do not submit AI generated pull requests.
• Please keep coverage at or above where it is when you clone the repo (yarn test --collectCoverage).